Electric switch



' C. BRAIVIMING.

ELECTRIC SWITCH.

APPLICATION FILED MAY 9. 1919.

1 ,83 3? Patented Mar. 2, 1920.

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U ITED STATES PATENT orrrcu.

v COMPANY, A CORPORATION OF ILLINOIS.

, Emma swI'I'cII.

Application filed May 9, 1919. Serial No. 295,865.

To all wkomz't may concern:

Be it known that I, CARI. BRAMMING, a citizen of the United States, and resident of Specification of Letters Patent.

Patented Mar. 2, 1920.

margins of'the insulating disk. The opening 23 is for the purpose of allowing spring 20 to seat on the insulation and is prefer- Chicago, county of Cook, and State of Illi-\ ably of such a size that said spring cannot nois have invented certain new and useful improvements in Electric Switches, of which the following is a specification, and which are illustrated in the accompanying drawings, forming a part thereof. Y

The invention relates to electric switches and has for its object the provision of a simple switch which will not readily get out of order, for use with currents of low volt- In the accompanying drawings Figure 1 is a plan view of the switch,

' Fig. 2 is a vertical detail section taken on the line 2-2 of Fig. 1,

Fig. 3 is a vertical section taken on the line 3-3 of Fig. 4, partly in elevation,

Fig. 4 is a horizontal section taken on the line 4-4 of Fig. 3,

Fig. 5 is a plan view of the device inverted, and

Fig. 6 is a perspective view of the lunger and cam elements removed from the evice.

The invention is illustrated as comprising a casing 10, an insulating base 11 and a top to the casing, as 12. The top 12 is centrally apertu'red to accommodate a push button. A face plate 13 is shown as fitting upon the top 12 and secured thereto by means of an upstanding flange at the margin of its aperture which flange is upset after the plate is applied. For more convenient reception of the terminals 15,, the casing is enlarged, as at 16. Terminals 15 are shown as secured to the inner side of insulation 11 by means of'screws 17, which screws in coaction with plates 18, also serve for the attachment of the wires to the switch. A guide member 19 projects upwardly from the insulating base 11 and serves as a positioning means for springs 20 and 21. Spring 20, as shown, is relatively weak as compared to spring 21.

The circuit is closed in this switch by means of a bridging element 22 adapted to be pressed into contact with terminals 15. This bridging element in the embodiment chosen for illustration takes the form of a disk of metal with an opening 23 atits central portion. A disk of insulating material, as 24, is shown secured to disk 22 as by turning the edges thereof upward and over the '26 suiiicient to depress cause of the relative come into contact with the metal of disk 22. Since spring 21 alsoseats on the insulation, at its opposite side, and the bridging element has no connection with any metal part of the switch, it follows that the electric current will flow through no part of the switch except terminals 15 and element 22. i

For theoperation of the device there is shown a plunger 26 which may be pressed by the fingerof the operator. This plunger 1s preferably axially recessed from its 111- ner end, as at 27, and the spring 21 projects into the recess and tends to hold the plunger in its retracted position as shown in Fig. 2. Pressure upon plun er the same will, estrength of springs 20 and 21, compress spring 20 to a greater extent than spring 21,, whereby bridging element 22 will be brought into contact with the terminals 15. p The end of the plunger 26 is shown reduced, as at 28, and passed through an opening in a disk 29 and -the end of the reduced portion 28 is flared outwardl soas to secure the disk to the plunger. H lation of the parts is such that disk 29 is freely revoluble on the end of the plunger26. In order that the circuit may be retained in a closed condition it'is necessary to provide means to hold the plunger in at least a partially advanced position such that spring 21 will be sufficiently compressed to overcome spring 20 and hold brid 'ng element 22 against the terminals 15. or this purpose I have provided disk 29 having owever, the reslots, as 32, in its margin and studs 36, 36,

projecting inwardly from the tubular casing. When slots 32 are in alinement with studs 36 spring 21 is free to press the plun ger to the position shown in Fig. 2 and the circuit will be open. it, now, the plunger be pressed so as to carry disk 29 below studs 36v and the disk be rotated, bringing slots 32 out of registry with studs 36, the plunger, when released, will be held in the partially advanced position shown in Fig. 3, with the circuit closed.

To provide the rotation referred to, a series of cams and an additional pair of studs 37 are supplied. These cams are preferably integral with the margin of disk 29 and project symmetrically in both directions therefrom. Four cam faces, 38, 39, are shown on each side of disk 29 and four non-active inclined surfaces 40, 41. Studs 37 are vertically spaced from studs 36 and are also circumferentially spaced through an arc of 45 degrees.

With the arts in the position of Fig. 2, if the plunger e depressed it will be seen that cam surface 38 will come into contact with stud 37 There being two studs 37 diametrically arranged and another cam surface 38 diametrically opposite to the one shown, two cams and two studs will come into action simultaneously. Due to the shape and unslotted points where the cam! surfaces reach the surface of the disk. The cam surfaces 38, 39, are, as shown, slightly longer than the non-active surfaces 40, 41. The disk having turned through an arc of 45 degrees and the studs 36 beingspaced from studs 37 circumferentially 45 degrees, studs 36 will, in the position of the disk above arrived at, lie opposite the outer end of cam surfaces 39, opposite cam surfaces 38 which have just acted. Therefore if the plunger be allowed to return under pressure of spring 21 the disk will be further revolved 45 degrees until studs 36 come into contact with the upper surface of the disk at unslotted positions. The parts will now 00-, cupy the ositions shown in Fig. 3 with the circuit he d closed.

The immediately following reciprocation of the plunger, meaning thereby both an inward and outward movement, will by action of the cams and studs, revolve the disk to a position 90 degrees removed from that shown in Fig. l, where the studs 36 will also register with the slots 32, and the circuit will be allowed to open.

I prefer to use the term reciprocation as being a complete movement lnward and outward of the plunger and it will be noted from the description given that alternate reciprocations leave the plunger retained in advanced position, as shown in Fig. 3, with the circuit closed, and the other of the alter nate reciprocations leave the plunger in the position shown in Fig. 2with the circuit open.

The insulating base 11 is shown as at-' tached to the casing by short studs 42, integral with the casing though other fastening means might be equally well utilized.

As stated, while four sets of cam surfaces and bent thereover,

are shown and two pairs of studs 36 and 37, a greater or less number could be used, the only requirement being that the circumferential separation of the upper and lower pairs of studs be such as to continue the revolution of the disk and that slots be provided separating alternate cam projections so that alternate reciprocations shall hold the plunger in advanced position. The studs are preferably arranged in pairs, diametrically arranged since this arrangement equalizes the stresses about the plunger and makes for smooth working of the switch.

I claim as my invention:

1. An electric switch comprising a casing, a pair of terminals carried by the casing, a bridging member housed within the casing and reciprocable therein,.reciprocating means movable independently of said member for holding said member in bridging relation to said terminals and means forbringing said reciprocating means into and releasing the same from holding action upon alternate reciprocations.

v2. An electric switch comprising a casing, a spring retracted plunger inclosed within the casing, a pair of terminals carried by said casing, a bridging contact member adapted to be pressed into contact with said terminals by said plunger when in a partially advanced position, a stud, a stop, cams coacting with the stud and sto said coacting parts being located on the p unger and on the casing respectively, said cams being configured to cause said stop to hold said plunger in a partially advanced position on come the weak spring and the circuit will be I held closed.

4. An electric switch comprising a pair of terminals, a reciprocating circuit closing member, a plurality of studs, a reciprocating plunger and cam surfaces coacting withone stud on the inward and with another stud on the outward movement of the plunger whereby one stud is caused to hold the lunger in an advanced position with the circuit closed on alternate reciprocations.

5. An electric switch comprising a casing, a reciprocating plunger, a cam disk revolubly mounted on said p unger, oppositely facing cams on said dis studs on said casing, one set coacting with one set of cams and cams whereby said disk is rotated by reciprocation of sald plunger, means whereby the circuit is held closed by an advanced position of said plunger, and means brought into action by the rotation of said disk whereby said plunger is retained in an advanced position upon alternate reciprocations.

6. An electric switch comprising a closed casing, a pair of terminals secured to an end of the casing, a stem projecting from the end of the casing within the same, a bridging member reciproca ble on said stem, a relatively weak spring pressing said bridging members from sald terminals, a hollow plunger reciprocable in said casing project ing from the end thereof opposite said terminals and-guided by said stem, a relatively strong sprin seated on said member and in the hollow oi said plunger surrounding said stem, whereby an advanced position of said plunger will hold said bridging member in contact with said terminals, and means acting upon alternate reciprocations of said plunger to hold same in an advanced position.

7 In an electric switch, in combination, a tubular casing, a reciprocable plunger, a freely revoluble disk secured to the end of said plunger, oppositely projecting. vertically acting cams secured to the edge of said disk and slidable in said casing, said cams bein symmetrical on opposite sides of said dis vertically and circumferentially spaced studs on the interior of said casing for coaction with said cams to cause the disk to rotate, the circumferential separation of the studs being sufiicient to induce the rotation caused by the two sets of cams to take place in the same direction, one set of studs acting on alternate reciprocations of the plunger to hold the cams and plungers in an advanced position, and means whereby an advanced position of the plunger will hold an electric circuit closed.

8. In an electric switch, in combination, a tubular casing, a reciprocable plunger, a disk freely revoluble on the end of said plunger and moving therewith, two sets of oppositely projecting vertically acting cams at the edge of said disk slidable within the casing and symmetrical about the disk, said cam surfaces on opposite sides of the disk converging to points of least throw at the surface of the disk at the same circumferential locations, slots in said disk at alternate points of least throw of the cams, pairs of diametrically opposite studs on the interior of the casing said pairs being vertically and circumferentially spaced whereby one stud of each pair coacts with one cam on its inward movement and the other stud with the opposite cam on its outward movement to cause rotation of the disk in one direction, said studs coacting with the disk to limit travel of the same thus holdmg the plunger in an advanced position and coacting with said slots to allow full travel of the disk on valternate reciprocations of the disk, and 

